SkyServer's tools allow you to access all publicly available data
from the Sloan Digital Sky Survey, one of the largest surveys of the night
sky ever made. You can use SDSS data to learn about the way the universe
works, or even to do original scientific research!

The Getting Started pages will tell you what types of data are
available on SkyServer, and which tools are best for accessing which types
of data. These tools give you many different ways
of looking at our data. Some tools also have help pages that will give you
more specific information on how to use the tool.

Types of Data

SkyServer offers access to many different types of data, but
most users will usually focus on four types: images,
spectra, photometric data, and spectroscopic data. The table below shows
what each type of data means:

Images

Pictures of celestial objects, stored as .jpg or .fits files

Spectra

Graphs of the amount of light emitted by an object at different
wavelengths. Spectra can be used to study the compositions and temperatures
of objects, as well as their distances from Earth.

Photometric Data

Various quantities measured from an object's image, such as its
brightness or size

Spectroscopic Data

Various quantities measured from an object's spectrum, such as
its spectral type or redshift.

To learn about the other types of data available on SkyServer, read
through the Schema Browser.

Tools

The table below gives a short description of each of SkyServer's tools,
listed from the most simple and general to the most complex and specialized.
The table also shows when you might use each tool, based on what information
you know already and what information you want to find out. Click on the name of
a tool for more information on what it does and how to use it.

Lets you navigate through the sky by panning and zooming. When you
click on an object, you get a summary of its photometric data. You can also
save objects in a notebook and export them to a spreadsheet program
for later analysis.

Lets you search the database for all objects that meet any criteria
you can think of, then returns whatever photometric or spectroscopic
data you request. The SQL search tool is the most powerful tool on SkyServer;
professional astronomers use a very similar tool in their research.